[Rails] Why is max-age in config.static_cache_control being ignored?

In config/environments/production.rb I have set

config.serve_static_assets = true

config.static_cache_control = "public, max-age=1000"

But the response header for application-fingerprint.css is something like the following where you can see max-age hasn't been changed to 1000. I'm assuming this is the result of some interaction with rack-cache but I don't know how to solve my problem.

Age:2943

Cache-Control:public, max-age=3600

Connection:Keep-Alive

Content-Encoding:gzip

Content-Length:13851

Content-Type:text/css

Date:Thu, 18 Oct 2012 01:24:20 GMT

Last-Modified:Sat, 13 Oct 2012 02:52:50 GMT

Server:WEBrick/1.3.1 (Ruby/1.9.3/2012-04-20)

Vary:Accept-Encoding

X-Content-Digest:94af71be4b455214a008971627ca52b848e40fc1

X-Rack-Cache:fresh

--
You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group.
To post to this group, send email to rubyonrails-talk@googlegroups.com.
To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msg/rubyonrails-talk/-/DRuhaghls7gJ.
For more options, visit https://groups.google.com/groups/opt_out.